Where These Chips Actually Lived

Chapters 2–9 studied both chips as pure engineering — transistors, registers, cycles, interrupts. This chapter grounds all of it in real machines and real markets: where minimalism and richness actually ended up, in products people bought by the millions. It's also where this course's own title finally gets fully explained — the "6510" has been sitting there unexplained since cpu8bit1-1.

The 6502's Real-World Footprint

• Apple II (1977) — Steve Wozniak's design, one of the machines that helped launch the personal computer industry as a mass-market category.
• Commodore PET, VIC-20, and Commodore 64 (the C64 in 1982) — one of the best-selling home computers of all time. The C64 specifically used the 6510, not a stock 6502 — a close variant adding an 8-bit I/O port used for bank-switching between ROM and RAM, but otherwise instruction-set identical to the 6502 this entire course has been teaching. This is finally the full explanation behind the course's own "6502/6510" title.
• Atari 2600 (1977) and later Atari 8-bit computers — the 2600 specifically used the 6507, a cut-down 6502 in a smaller, cheaper package with fewer address lines.
• Nintendo Entertainment System (1983 Japan / 1985 US) — powered by the Ricoh 2A03, a 6502 derivative widely reported to have had its decimal mode (cpu8bit1-3's own D flag) deliberately removed to avoid a licensing fee tied to that specific circuitry.

The Z80's Real-World Footprint

• Sinclair ZX Spectrum (1982) — hugely influential across the UK and European home computing scene, home to an enormous game library and demoscene.
• The MSX standard — a Japanese-led standardized home computer platform adopted by multiple manufacturers, all sharing Z80-based compatibility.
• Amstrad CPC series — another major European Z80-based home computer line.
• The original Nintendo Game Boy (1989) — powered by the Sharp LR35902, a genuine Z80 derivative that removes the shadow register set and IX/IY entirely, while adding a small number of its own new instructions.
• CP/M — the dominant business and professional operating system of the late 1970s and early 1980s, running primarily on Z80-based (and 8080-compatible) machines — a huge share of the Z80's real commercial footprint that had nothing to do with games at all, made possible directly by cpu8bit1-5's own 8080-compatibility story.

A Shared Pattern — Both Chips Spawned Cost/Licensing-Driven Derivatives

It's worth naming the parallel directly: both chips ended up inside an iconic games console via a derivative that deliberately removed something for cost or licensing reasons. The 6502 became the NES's 2A03 by losing decimal mode; the Z80 became the Game Boy's LR35902 by losing its entire shadow register set — the exact feature cpu8bit1-9 just finished showing off as the Z80's own genuine interrupt-handling advantage. Even in real hardware built directly from these two chips, the same kind of trade-off this whole course has been tracing — what's worth keeping, what's worth cutting — kept happening all over again, one generation later.

Both Are Still Actively Used Today

Neither chip is a purely historical curiosity. WDC (Western Design Center), founded by Bill Mensch — one of the 6502's own original co-designers named back in cpu8bit1-2 — still designs, produces, and licenses modern 6502-family cores today. The Z80 itself remained in continuous commercial production for an extraordinarily long stretch — decades — before shifting primarily toward licensed IP cores rather than standalone chips. Both architectures also have genuinely active hobbyist communities today, building homebrew computers, new games, and demos on real (or faithfully compatible) hardware, not just studying them as history.

Hands-On Exercises